Various machine assemblies utilized in vehicle and industrial applications, such as gas turbine engines, are regularly inspected to ensure safe and reliable performance of the machine assemblies. The regular inspections may be required as part of a service agreement. During an inspection, the machine assembly may be transported to a service shop, wherein the machine assembly is disassembled to its component parts. Various component parts or work pieces of the machine assembly are individually inspected for defects or anomalies, such as spallation, cracks, nicks, scratches, kinks, pits, or the like. The presence of defects or anomalies indicates that the part may be damaged and could risk the integrity of the machine assembly if reassembled into the machine assembly. Typically, such inspections are manually performed by a human operator that inspects the parts by hand. If the operator detects a defect, the operator may consider various factors such as the type of defect, the size of the defects, and the like, to determine whether to scrap or discard the part, repair the part, or approve the part for reuse within the machine assembly without repair.
Some known manual processes for detailed part inspection are subjective, inconsistent, inefficient, and inaccurate. For example, the process is subject to inherent human bias and/or error of the operator. Although there may be adopted guidelines or rules for the operator to follow when determining what constitutes a defect worthy of repairing the part and/or discarding the part, two different operators may have different interpretations and/or applications of the guidelines.
Furthermore, some known processes for detailed part inspection may be inaccurate based at least in part on inconsistent or limited lighting of the part. Lighting variations, specular reflection of the light from the part surface, view point variations, and the like, may result in defect prediction inaccuracies and uncertainties. For example, a particular defect on a surface of a work piece may not be sufficiently visible to an operator (or even an automated detection system) when illuminated by a first light that has a first incident angle relative to the surface and a first wavelength range and intensity, but the same defect may be readily noticeable when illuminated by a second light having a different incident angle, wavelength range, and/or intensity than the first light. Furthermore, a different defect in the surface of the part may be more noticeable under the first light than the second light. The accuracy and certainty of some known inspection processes may be compromised based on such inconsistent and/or limited lighting of the parts.